A position sensorless control method, system, device and storage medium

Abstract

The invention discloses a position sensorless control method, system, device and storage medium. The method comprises: building an extended state observer based on a permanent magnet synchronous motor model, establishing a transfer function between the observation error of the back electromotive force of the extended state observer and the derivative of the back electromotive force, and designing a back electromotive force observation error adaptive law in which the parameters of the extended state observer change with the speed; building a speed adaptive extended state observer according to the back electromotive force observation error adaptive law to obtain the equivalent back electromotive force observation value of the α axis and the equivalent back electromotive force observation value of the β axis in a two-phase stationary coordinate system of the permanent magnet synchronous motor; using a phase-locked loop based on the extended state observer to process the above back electromotive force observation value to obtain the speed estimation value and angle estimation value of the permanent magnet synchronous motor; the invention can improve the observation accuracy and the reliability of the motor drive system.

Description

Technical Field

[0001] The present invention relates to a sensor control method, system, device and storage medium, and in particular to a position sensorless control method, system, device and storage medium, belonging to the technical field of motor control. Background Art

[0002] Permanent magnet synchronous motors rely on permanent magnet excitation and have the advantages of simple structure, high torque density and high efficiency. They are now widely used in new energy vehicles, robots, CNC machine tools and other fields.

[0003] In the speed regulation system of traditional permanent magnet synchronous motors, photoelectric encoders, rotary transformers, etc. are usually used to obtain rotor position and speed information. These devices are relatively accurate, but have disadvantages such as increased size, increased cost, and susceptibility to failure due to external environment. The use of a position sensorless control method can solve these problems. Position sensorless control methods are generally divided into zero-speed and low-speed position sensorless technology and medium- and high-speed position sensorless technology. Medium- and high-speed position sensorless technology obtains rotor position and speed information through back-electromotive force or flux linkage model. This type of method includes extended state observer method, sliding mode observer method, Kalman filter method, effective flux linkage observer method, model reference adaptation, etc. Among them, the extended state observer method has high observation accuracy, strong anti-disturbance ability, more convenient parameter adjustment, and can realize frequency domain analysis, so the present invention uses the extended state observer method.

[0004] At present, most of the applications of extended state observers are based on the performance design of a certain rated speed operating point with fixed parameters. However, the back EMF estimation accuracy of the fixed parameter extended state observer will decrease with the increase of speed, and the accuracy of estimated rotor position and speed will decrease. Therefore, it is of great significance to use an extended state observer with speed adaptation.

[0005] After estimating the back EMF, the position sensorless control system can directly calculate the rotor position through the inverse tangent. However, the speed is derived from the differential of the rotor position, and the noise cannot be suppressed. In addition, the accuracy of the rotor position estimation is affected by the estimated back EMF waveform. The phase-locked loop obtains the speed information through the integration of the PI link without the need for differential operations. It has been widely used. However, the traditional PI-based phase-locked loop can only cope with the situation where the speed changes slowly. When the speed changes rapidly, there will be a problem of poor estimation performance.

[0006] To address the above problems, the traditional method uses the relationship between current observation error, speed, and observer bandwidth to establish an observer. Although this ensures that the current observation error remains within a certain range when the speed increases, it does not solve the problem that the back-EMF observation error changes with speed. Summary of the invention

[0007] Purpose of the invention: The purpose of the present invention is to provide a position sensorless control method, system, device and storage medium that can improve the observation accuracy and reliability of the motor drive system.

[0008] Technical solution: A position sensorless control method according to the present invention comprises:

[0009] S1: Based on the permanent magnet synchronous motor model, an extended state observer is constructed, a transfer function is established between the observation error of the back-EMF of the extended state observer and the derivative of the back-EMF, and an adaptive law of the back-EMF observation error is designed with the parameters of the extended state observer changing with the speed;

[0010] S2: According to the adaptive law of the back-EMF observation error, a speed adaptive extended state observer is constructed to obtain the equivalent back-EMF observation value of the α-axis in the two-phase stationary coordinate system of the permanent magnet synchronous motor. and the equivalent back EMF observed value of the β axis

[0011] S3: The back EMF observations are processed using a phase-locked loop based on an extended state observer to obtain the estimated speed of the permanent magnet synchronous motor. and the angle estimate

[0012] Furthermore, the method for establishing the permanent magnet synchronous motor model described in step S1 is as follows:

[0013] First, establish the mathematical model of the permanent magnet synchronous motor in the two-phase stationary coordinate system:

[0014]

[0015] Where: i α 、i β are the α and β phase stator currents respectively, i αβ =[i α i β ] T 、u αβ =[u α u β ] T and e αβ =[e α e β ] T are the stator current, stator voltage and back EMF in the two-phase stationary coordinate system respectively; R, ψ f , k e and L s Respectively represent the stator phase resistance, rotor flux, induced electromotive force coefficient and inductance parameter values; ω e is the rotor electrical angular velocity, θ e is the rotor electrical angle; i α 、iβ The collected three-phase current i a ,i b ,i c After 3s / 2s transformation, we get: u α 、u β The stator voltage given value u d 、u q After 2r / 2s transformation, we get:

[0016] Furthermore, in step S1, based on the permanent magnet synchronous motor model, an extended state observer is constructed, and a transfer function is established between the observation error of the back electromotive force of the extended state observer and the derivative of the back electromotive force, specifically:

[0017] According to the mathematical model of the permanent magnet synchronous motor in the two-phase stationary coordinate system, an extended state observer is established with the stator current as the state variable and the back electromotive force as the extended variable.

[0018] The back electromotive force of the α and β axes is taken as the state variable of the expansion, and x 11 =[i α i β ] T x 12 =[-k e e α -k e e β ] T =f, u=[u α u β ] T , expand (1) into the following formula:

[0019]

[0020] Then the extended state observer is established:

[0021]

[0022] where e 11 represents the observation error of the stator current, β 11 , β 12 is the feedback gain coefficient of the extended state observer; z 11 =[z 1α z 1β ] T represents the observed value of the stator current in the two-phase stationary coordinate system; z 12 =[z 2α z 2β ] T represents the observed value of the back EMF, k e =1 / Ls ;

[0023] From equations (3) and (4), the error equation of the extended state observer can be obtained as follows:

[0024]

[0025] where e 12 represents the observation error of the back EMF;

[0026] The α and β phases are symmetrical. Taking the α phase as the object for analysis, the transfer function between the observation error of the extended state observer and the back EMF can be obtained from equation (5):

[0027]

[0028] Where s represents the complex frequency.

[0029] Furthermore, the design of the back-EMF observation error adaptive law of the extended state observer parameters changing with the speed in step S1 is specifically as follows:

[0030] Assume β 11 -A=2ω0、 Where ω0 is the bandwidth of the extended state observer, and equation (6) is transformed into:

[0031]

[0032] Transforming equation (7) into the frequency domain, we can obtain:

[0033]

[0034] Where j is the imaginary unit and ω is the angular frequency;

[0035] The amplitude-frequency response of the back-EMF observation error is obtained from formula (8):

[0036]

[0037] Since ω<<ω0, we can get from formula (9):

[0038]

[0039] Where C is a constant greater than 2; the maximum back EMF error observation amplitude can be expressed as:

[0040]

[0041] in is the derivative of x2, expressed as:

[0042]

[0043] From formula (12), we can get The upper bound of is:

[0044]

[0045] From formula (13), we can get e 12 The absolute value at time t in the time domain is:

[0046]

[0047] Similarly, the current estimation error e can be obtained 11 for:

[0048]

[0049] The current estimation error e is obtained from equations (14) and (15): 11 Estimation error of back EMF 12 Relationship:

[0050] e 11 |Cω0=|e 12 | (16)

[0051] From formula (14), the adaptive law of back-EMF observation error of the extended state observer with the speed change can be obtained as follows:

[0052]

[0053] in is the rated maximum back EMF observation error value.

[0054] Furthermore, the speed adaptive extended state observer in step S2 is obtained by substituting the back-EMF observation error adaptive law into the extended state observer in step S1.

[0055] Furthermore, the step S3 specifically includes:

[0056] The back EMF observation value based on the output of the speed adaptive extended state observer is used as the input of the phase-locked loop, and the angle error is calculated according to the following formula:

[0057]

[0058] The derivative relationship between the motor electrical angle, speed, and angular acceleration is:

[0059]

[0060] Among them: a e is the angular acceleration, d is the derivative of the angular acceleration; let: x 21 =θ e , x 22 =ωe , x 23 =a e ; Convert equation (19) to:

[0061]

[0062] The extended state observer in the phase-locked loop is established by equation (20):

[0063]

[0064] Where: e 21 Represents θ e The observation error value of z 21 Represents θ e The observed value of z 22 Represents ω e The observed value of z 23 Indicates a e Observed value of β 21 , β 22 , β 23 is the feedback gain coefficient of the extended state observer;

[0065] From formula (21), the transfer function of the phase-locked loop position estimation based on the extended state observer can be obtained as:

[0066]

[0067] Where s represents the complex frequency; according to the bandwidth method, the observer gain is adjusted as:

[0068] [β 21 β 22 β 23 ]=[3σ03σ0 2 σ0 3 ] (twenty three)

[0069] Where σ0 is the bandwidth of the extended state observer in the phase-locked loop.

[0070] Based on the same inventive concept, the present invention also provides a position sensorless control system, comprising:

[0071] A design module is used to build an extended state observer based on a permanent magnet synchronous motor model, establish a transfer function between the observation error of the back-EMF of the extended state observer and the derivative of the back-EMF, and design an adaptive law of the back-EMF observation error when the extended state observer parameters change with the speed;

[0072] A construction module is used to construct a speed adaptive extended state observer according to the back-EMF observation error adaptive law to obtain the equivalent back-EMF observation value of the α-axis in the two-phase stationary coordinate system of the permanent magnet synchronous motor. and the equivalent back EMF observed value of the β axis

[0073] A control module is used to process the back EMF observation value using a phase-locked loop based on an extended state observer to obtain a speed estimation value of the permanent magnet synchronous motor. and the angle estimate

[0074] Furthermore, the design module is specifically implemented as follows:

[0075] First, establish the mathematical model of the permanent magnet synchronous motor in the two-phase stationary coordinate system:

[0076]

[0077] Where: i α 、i β are the α and β phase stator currents respectively, i αβ =[i α i β ] T 、u αβ =[u α u β ] T and e αβ =[e α e β ] T are the stator current, stator voltage and back EMF in the two-phase stationary coordinate system respectively; R, ψ f , k e and L s Respectively represent the stator phase resistance, rotor flux, induced electromotive force coefficient and inductance parameter values; ω e is the rotor electrical angular velocity, θ e is the rotor electrical angle; i α 、i β The collected three-phase current i a ,i b ,i c After 3s / 2s transformation, we get: u α 、u β The stator voltage given value u d 、u q After 2r / 2s transformation, we get:

[0078] According to the mathematical model of the permanent magnet synchronous motor in the two-phase stationary coordinate system, an extended state observer is established with the stator current as the state variable and the back electromotive force as the extended variable.

[0079] The back electromotive force of the α and β axes is taken as the state variable of the expansion, and x 11 =[iα i β ] T x 12 =[-k e e α -k e e β ] T =f, u=[u α u β ] T , expand (1) into the following formula:

[0080]

[0081] Then the extended state observer is established:

[0082]

[0083] where e 11 represents the observation error of the stator current, β 11 , β 12 is the feedback gain coefficient of the extended state observer; z 11 =[z 1α z 1β ] T represents the observed value of the stator current in the two-phase stationary coordinate system; z 12 =[z 2α z 2β ] T represents the observed value of the back EMF, k e =1 / L s ;

[0084] From equations (3) and (4), the error equation of the extended state observer can be obtained as follows:

[0085]

[0086] where e 12 represents the observation error of the back EMF;

[0087] The α and β phases are symmetrical. Taking the α phase as the object for analysis, the transfer function between the observation error of the extended state observer and the back EMF can be obtained from equation (5):

[0088]

[0089] Where s represents the complex frequency;

[0090] Assume β 11 -A=2ω0、 Where ω0 is the bandwidth of the extended state observer, and equation (6) is transformed into:

[0091]

[0092] Transforming equation (7) into the frequency domain, we can obtain:

[0093]

[0094] Where j is the imaginary unit and ω is the angular frequency;

[0095] The amplitude-frequency response of the back-EMF observation error is obtained from formula (8):

[0096]

[0097] Since ω<<ω0, we can get from formula (9):

[0098]

[0099] Where C is a constant greater than 2; the maximum back EMF error observation amplitude can be expressed as:

[0100]

[0101] in is the derivative of x2, expressed as:

[0102]

[0103] From formula (12), we can get The upper bound of is:

[0104]

[0105] From formula (13), we can get e 12 The absolute value at time t in the time domain is:

[0106]

[0107] Similarly, the current estimation error e can be obtained 11 for:

[0108]

[0109] The current estimation error e is obtained from equations (14) and (15): 11 Estimation error of back EMF 12 Relationship:

[0110] e 11 |Cω0=|e 12 | (16)

[0111] From formula (14), the adaptive law of back-EMF observation error of the extended state observer with the speed change can be obtained as follows:

[0112]

[0113] in is the rated maximum back EMF observation error value.

[0114] Based on the same inventive concept, the present invention also provides a position sensorless control device, comprising: one or more processors, one or more memories and one or more programs, wherein the programs are stored in the memories and configured to be executed by the processors, and when the programs are loaded into the processors, the steps of the position sensorless control method described in any one of the above items are implemented.

[0115] Based on the same inventive concept, the present invention also provides a storage medium for position sensorless control, wherein the storage medium stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a processor, the processor executes the steps of the position sensorless control method described in any one of the above items.

[0116] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The extended state observer based on the adaptive law of back-EMF observation error reduces the observation error when the speed changes through speed adaptation, improves the observation accuracy, and improves the reliability of the motor drive system; (2) The present invention derives the adaptive law based on the relationship between the back-EMF estimation error and the speed. Compared with the method of deriving the adaptive law based on the relationship between the current observation error and the speed, it not only ensures that the back-EMF estimation error is within a certain range, but also the value of the current observation error decreases with the increase of the speed, further improving the observation accuracy; (3) Compared with the phase-locked loop based on PI, the phase-locked loop based on the extended state observer has a lower angular position estimation error when the speed changes, further improving the observation accuracy of the system; (4) The method proposed in the present invention does not require additional hardware equipment, but only needs to be implemented from the software control strategy, without adding additional costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0117] Figure 1 is a flow chart of a method according to an embodiment of the present invention;

[0118] Figure 2 It is a principle framework diagram of an embodiment of the present invention;

[0119] Figure 3 It is a principle framework diagram of a speed adaptive extended state observer according to an embodiment of the present invention;

[0120] Figure 4 This is a principle framework diagram of a phase-locked loop based on an extended state observer according to an embodiment of the present invention;

[0121] Figure 5It is the simulation diagram of the traditional extended state observer and the estimated speed and actual speed based on the PI phase-locked loop;

[0122] Figure 6 It is a simulation diagram of the estimated speed and the actual speed of an embodiment of the present invention;

[0123] Figure 7 It is the simulation diagram of the traditional extended state observer and the speed error estimated based on the PI phase-locked loop;

[0124] Figure 8 4 is a simulation diagram of the estimated rotation speed error according to an embodiment of the present invention. DETAILED DESCRIPTION

[0125] In order to make the technical solutions and advantages of the present invention more clearly understood, the technical solutions of the present invention are further described below in conjunction with the accompanying drawings and embodiments.

[0126] As attached Figure 1 As shown, the position sensorless control method of this embodiment includes:

[0127] S1: Based on the permanent magnet synchronous motor model, an extended state observer is constructed, a transfer function is established between the observation error of the back-EMF of the extended state observer and the derivative of the back-EMF, and an adaptive law of the back-EMF observation error is designed with the parameters of the extended state observer changing with the speed;

[0128] S2: According to the adaptive law of the back-EMF observation error, a speed adaptive extended state observer is constructed to obtain the equivalent back-EMF observation value of the α-axis in the two-phase stationary coordinate system of the permanent magnet synchronous motor. and the equivalent back EMF observed value of the β axis

[0129] S3: The back EMF observations are processed using a phase-locked loop based on an extended state observer to obtain the estimated speed of the permanent magnet synchronous motor. and the angle estimate

[0130] The principle framework of the permanent magnet synchronous motor position sensorless control system corresponding to this embodiment is as follows: Figure 2 shown.

[0131] Module 6 is 3s / 2s coordinate transformation, the expression is:

[0132]

[0133] Module 5 is the 2r / 2s coordinate transformation, and the expression is:

[0134]

[0135] Module 7 is 2s / 2r coordinate transformation, the expression is:

[0136]

[0137] The stator current i obtained by module 4 a ,i b ,i c After the 3s / 2s coordinate transformation module 6, the current command i in the two-phase stationary coordinate system is obtained. α ,i β .

[0138] The current command i α ,i β The voltage command u output by the 2r / 2s coordinate transformation module 5 is input into the extended state observer module 11 based on the back electromotive force observation error adaptive law. α ,u β The speed is input into the extended state observer module 11 based on the adaptive law of the back-EMF observation error, and the observed speed output by the phase-locked loop is The back-EMF observation error adaptive law is used as the input to the extended state observer module 11, which outputs the back-EMF observation value based on the back-EMF observation error adaptive law. and

[0139] Back EMF Observation Value and Input to the phase-locked loop module 12 based on the extended state observer to estimate the rotor position observation value and speed observations

[0140] The rotor position observation value is obtained The speed observation value n is fed back to the speed input terminal and n * After comparison, the current is input to the speed loop regulator module 10, and the current is obtained after regulation by the module 10.

[0141] The current i output by the 2s / 2r coordinate transformation module 7 d and i q , current i d With the d-axis current given reference value d * After comparison, it is input to the current loop regulator module 8 and outputs the d-axis voltage The current output by the speed loop regulator module 10 With current i q After comparison, it is input to the current loop regulator module 9 and outputs the q-axis voltage

[0142] Voltage command and After the 2r / 2s coordinate transformation module 5, the voltage command u in the two-phase stationary coordinate system is obtained. α ,u β . Set the voltage command u α ,u β The signal is input into the SVPWM module 3 , which outputs a PWM drive signal, and then drives the permanent magnet synchronous motor module 1 through the inverter module 2 .

[0143] The position sensorless control method of this embodiment is as follows:

[0144] Step S1: according to the mathematical model of the permanent magnet synchronous motor in the two-phase stationary coordinate system, an extended state observer is established with the stator current as the state variable and the back electromotive force as the extended variable;

[0145] First, a mathematical model of the permanent magnet synchronous motor in a two-phase stationary coordinate system is established. The mathematical model is as follows:

[0146]

[0147] Where: i αβ =[i α i β ] T ,u αβ =[u α u β ] T , e αβ =[e α e β ] T are the stator current, stator voltage and back EMF in the two-phase stationary coordinate system respectively;

[0148] R, ψ f , k e , L s They represent the stator phase resistance, rotor flux, induced electromotive force coefficient and inductance parameter values ​​respectively;

[0149] ω e is the rotor electrical angular velocity, θ e is the rotor electrical angle;

[0150] where i α 、i β The collected three-phase current i a ,i b ,i c After module 6, 3s / 2s transformation is obtained as shown in the following formula:

[0151]

[0152] uα 、u β The stator voltage given value is transformed by module 5, 2r / 2s, as shown in the following formula:

[0153]

[0154] The back electromotive force of the α and β axes is taken as the state variable of the expansion, and

[0155] x 11 =]i α i β [ T x 12 =[-k e e α -k e e β [ T =f, Then formula (1) can be expanded into the following form:

[0156]

[0157] The extended state observer is established as follows:

[0158]

[0159] where e 11 represents the observation error of the stator current;

[0160] z 11 =[z 1α z 1β ] T represents the observed value of the stator current in the two-phase stationary coordinate system;

[0161] z 12 =[z 2α z 2β ] T represents the observed value of the back EMF, k e =1 / L s ;

[0162] From equations (3) and (4), the error equation of the extended state observer can be obtained as follows:

[0163]

[0164] where e 12 represents the observation error of the back EMF;

[0165] Since the α and β phases are symmetrical, the α phase is taken as the object for analysis. From equation (5), the transfer function between the observation error of the back EMF of the extended state observer and the back EMF is:

[0166]

[0167] Assume β 11 -A=2ω0、 Where ω0 is the bandwidth of the extended state observer, and equation (6) is:

[0168]

[0169] Transforming equation (7) into the frequency domain, we can obtain:

[0170]

[0171] From formula (8), the amplitude-frequency response of the back-EMF observation error can be obtained as follows:

[0172]

[0173] Since ω<<ω0, we can get from formula (9):

[0174]

[0175] Where C is a constant greater than 2.

[0176] The maximum back EMF error observed amplitude can be expressed as:

[0177]

[0178] in is the derivative of x2, which can be expressed as:

[0179]

[0180] From formula (12), we can get The upper bound of is:

[0181]

[0182] From formula (13), we can get e 12 The absolute value at time t in the time domain is:

[0183]

[0184] Similarly, the current estimation error e can be obtained 11 for:

[0185]

[0186] From equations (14) and (15), we can get the current estimation error e 11 Estimation error of back EMF 12 Relationship:

[0187] e 11|Cω0=|e 12 | (16)

[0188] From formula (16), we can see that e 11 With e 12 There is a relationship with Cω0 as a multiple, if e 11 The relationship between the speed and the derived parameter adaptive law ensures that e 11 The value of is within a certain range, but as the speed increases, ω0 also increases. At this time, the back EMF estimation error e 12 The present invention estimates the error e based on the back electromotive force 12 The adaptive law is derived from the relationship between the speed and the back EMF estimation error e 12 Within a certain range, and e 11 The value of will decrease with the increase of rotation speed, further improving the observation accuracy.

[0189] Formula (11) is a frequency domain description, which represents the back EMF observation error value e 12 The amplitude under the sinusoidal steady-state response; Equation (14) is a time domain description, which represents the back EMF observation error value e at time t 12 It can be seen that the back EMF observation error value e 12 At any time it will not exceed

[0190] From formula (14), the adaptive law of back-EMF observation error of the extended state observer with the speed change can be obtained as follows:

[0191]

[0192] in is the rated maximum back EMF observation error value.

[0193] Step S2: Substituting equation (17) into equation (4) yields the extended state observer based on the adaptive law of back-EMF observation error according to the present invention, namely, the speed adaptive extended state observer, as follows: Figure 3 As shown, the extended state observer based on the back-EMF observation error adaptive law observes the back-EMF The principle is that due to the symmetry of the αβ axis, the structural block diagram for observing the β axis back electromotive force can be obtained by the same logic.

[0194] Step 3 is as follows:

[0195] The back-EMF observation value output by the speed adaptive extended state observer based on the back-EMF observation error adaptive law is used as the input of the phase-locked loop, as shown in Figure 4 As shown; the angle error is calculated according to the following relationship:

[0196]

[0197] The derivative relationship between the motor electrical angle, speed, and angular acceleration is:

[0198]

[0199] Among them: a e is the angular acceleration, and d is the derivative of the angular acceleration. Let: x 21 =θ e , x 22 =ω e , x 23 =a e . We can get formula (19) as follows:

[0200]

[0201] The extended state observer in the phase-locked loop is established by equation (20):

[0202]

[0203] Where: e 21 Represents θ e The observation error value of z 21 Represents θ e The observed value of z 22 Represents ω e The observed value of z 23 Indicates a e Observed value of β 21 , β 22 , β 23 is the feedback gain coefficient of the extended state observer. It should be noted that the position estimation error of the extended state observer is defined as The output error in equation (18) is defined as Therefore, a negative unity gain link is added to the error forward path to achieve sign conversion.

[0204] From formula (21), the transfer function of the phase-locked loop position estimation based on the extended state observer can be obtained as:

[0205]

[0206] According to the “bandwidth method”, the observer gain can be adjusted as:

[0207] [β 21 β 22 β 23 ]=[3σ03σ0 2 σ0 3 ] (twenty three)

[0208] Where σ0 is the bandwidth of the extended state observer in the phase-locked loop.

[0209] All angles mentioned in the present invention are electrical angles.

[0210] Through Matlab / Simulink simulation verification, the motor parameters are shown in Table 1:

[0211] Table 1 Motor parameters

[0212]

[0213] The speed is estimated by using an extended state observer based on the adaptive law of back-EMF observation error and a phase-locked loop based on the extended state observer, such as Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown in the figure, when the speed changes, compared with the traditional extended state observer and the PI-based phase-locked loop, the estimated speed error fluctuates less, the time to reach the stable speed is shorter, and it has better estimation performance.

[0214] Based on the same inventive concept, the present invention also provides a position sensorless control system, comprising:

[0215] A design module is used to build an extended state observer based on a permanent magnet synchronous motor model, establish a transfer function between the observation error of the back-EMF of the extended state observer and the derivative of the back-EMF, and design an adaptive law of the back-EMF observation error when the extended state observer parameters change with the speed;

[0216] A construction module is used to construct a speed adaptive extended state observer according to the back-EMF observation error adaptive law to obtain the equivalent back-EMF observation value of the α-axis in the two-phase stationary coordinate system of the permanent magnet synchronous motor. and the equivalent back EMF observed value of the β axis

[0217] A control module is used to process the back EMF observation value using a phase-locked loop based on an extended state observer to obtain a speed estimation value of the permanent magnet synchronous motor. and the angle estimate

[0218] Furthermore, the design module is specifically implemented as follows:

[0219] First, establish the mathematical model of the permanent magnet synchronous motor in the two-phase stationary coordinate system:

[0220]

[0221] Where: i α 、i β are the α and β phase stator currents respectively, i αβ =[i α iβ ] T 、u αβ =[u α u β ] T and e αβ =[e α e β ] T are the stator current, stator voltage and back EMF in the two-phase stationary coordinate system respectively; R, ψ f , k e and L s Respectively represent the stator phase resistance, rotor flux, induced electromotive force coefficient and inductance parameter values; ω e is the rotor electrical angular velocity, θ e is the rotor electrical angle; i α 、i β The collected three-phase current i a ,i b ,i c After 3s / 2s transformation, we get: u α 、u β The stator voltage given value u d 、u q After 2r / 2s transformation, we get:

[0222] According to the mathematical model of the permanent magnet synchronous motor in the two-phase stationary coordinate system, an extended state observer is established with the stator current as the state variable and the back electromotive force as the extended variable.

[0223] The back electromotive force of the α and β axes is taken as the state variable of the expansion, and x 11 =[i α i β ] T x 12 =[-k e e α -k e e β ] T =f, u=[u α u β ] T , expand (1) into the following formula:

[0224]

[0225] Then the extended state observer is established:

[0226]

[0227] where e 11represents the observation error of the stator current, β 11 , β 12 is the feedback gain coefficient of the extended state observer; 11 =[z 1α z 1β ] T represents the observed value of the stator current in the two-phase stationary coordinate system; z 12 =[z 2α z 2β ] T represents the observed value of the back EMF, k e =1 / L s ;

[0228] From equations (3) and (4), the error equation of the extended state observer can be obtained as follows:

[0229]

[0230] where e 12 represents the observation error of the back EMF;

[0231] The α and β phases are symmetrical. Taking the α phase as the object for analysis, the transfer function between the observation error of the extended state observer and the back EMF can be obtained from equation (5):

[0232]

[0233] Where s represents the complex frequency;

[0234] Assume β 11 -A=2ω0、 Where ω0 is the bandwidth of the extended state observer, and equation (6) is transformed into:

[0235]

[0236] Transforming equation (7) into the frequency domain, we can obtain:

[0237]

[0238] Where j is the imaginary unit and ω is the angular frequency;

[0239] The amplitude-frequency response of the back-EMF observation error is obtained from formula (8):

[0240]

[0241] Since ω<<ω0, we can get from formula (9):

[0242]

[0243] Where C is a constant greater than 2; the maximum back EMF error observation amplitude can be expressed as:

[0244]

[0245] in is the derivative of x2, expressed as:

[0246]

[0247] From formula (12), we can get The upper bound of is:

[0248]

[0249] From formula (13), we can get e 12 The absolute value at time t in the time domain is:

[0250]

[0251] Similarly, the current estimation error e can be obtained 11 for:

[0252]

[0253] The current estimation error e is obtained from equations (14) and (15): 11 Estimation error of back EMF 12 Relationship:

[0254] |e 11 |Cω0=|e 12 | (16) From formula (14), the adaptive law of back-EMF observation error of the extended state observer parameters changing with the speed is:

[0255]

[0256] in is the rated maximum back EMF observation error value.

[0257] Based on the same inventive concept, this embodiment also provides a position sensorless control device, including: one or more processors, one or more memories and one or more programs, wherein the programs are stored in the memories and configured to be executed by the processors, and when the programs are loaded into the processors, the steps of the position sensorless control method described in any one of the above items are implemented.

[0258] Based on the same inventive concept, this embodiment also provides a storage medium for position sensorless control, wherein the storage medium stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a processor, the processor executes the steps of the position sensorless control method described in any one of the above items.

[0259] The present invention provides a position sensorless control method, in which the observation error e of the back electromotive force of the expanded state observer is 12 A transfer function is established between the derivative of the back-EMF and an extended state observer based on the adaptive law of back-EMF observation error is proposed. Compared with the observer of the traditional method, it can not only ensure that the back-EMF observation error remains within a certain range when the speed increases, but also the current observation error decreases with the increase of the speed. Under the setting of the maximum error value of the same order of magnitude, the current observation error of the extended state observer based on the adaptive law of back-EMF observation error proposed by the present invention is also much smaller than that of the traditional method. At the same time, a phase-locked loop based on the extended state observer is proposed to estimate the rotor position and speed, further improving the estimation performance of the position sensorless control system.

Claims

1. A position sensorless control method, characterized in that: include: S1: Based on the permanent magnet synchronous motor model, an extended state observer is constructed, a transfer function is established between the observation error of the back-EMF of the extended state observer and the derivative of the back-EMF, and an adaptive law of the back-EMF observation error of the extended state observer parameters changing with the speed is designed; the permanent magnet synchronous motor model establishment method is as follows: First, establish the mathematical model of the permanent magnet synchronous motor in the two-phase stationary coordinate system: Where: i α 、i β are the α and β phase stator currents respectively, i αβ =[i α i β ] T 、u αβ =[u α u β ] T and e αβ =[e α e β ] T are the stator current, stator voltage and back EMF in the two-phase stationary coordinate system respectively; R, ψ f , k e and L s Respectively represent the stator phase resistance, rotor flux, induced electromotive force coefficient and inductance parameter values; ω e is the rotor electrical angular velocity, θ e is the rotor electrical angle; i α 、i β The collected three-phase current i a ,i b ,i c After 3s / 2s transformation, we get: u α 、u β The stator voltage given value u d 、u q After 2r / 2s transformation, we get: Based on the permanent magnet synchronous motor model, an extended state observer is built, and a transfer function is established between the observation error of the back electromotive force of the extended state observer and the derivative of the back electromotive force, specifically: According to the mathematical model of the permanent magnet synchronous motor in the two-phase stationary coordinate system, an extended state observer is established with the stator current as the state variable and the back electromotive force as the extended variable. The back electromotive force of the α and β axes is taken as the state variable of the expansion, and x 11 =[i α i β ] T x 12 =[-k e e α -k e e β ] T =f, u=[u α u β ] T , expand (1) into the following formula: Then the extended state observer is established: where e 11 represents the stator current observation error, β 11 , β 12 is the feedback gain coefficient of the extended state observer; z 11 =[z 1α z 1β ] T represents the observed value of the stator current in the two-phase stationary coordinate system; z 12 =[z 2α z 2β ] T represents the observed value of the back EMF, k e =1 / L s ; From equations (3) and (4), the error equation of the extended state observer can be obtained as follows: where e 12 represents the back EMF observation error; The α and β phases are symmetrical. Taking the α phase as the object for analysis, the transfer function between the observation error of the extended state observer and the back EMF can be obtained from equation (5): Where s represents the complex frequency; The designed extended state observer parameter changes with the speed of the back-EMF observation error adaptive law, specifically, Assume β 11 -A=2ω0、 Where ω0 is the bandwidth of the extended state observer, and equation (6) is transformed into: Transforming equation (7) into the frequency domain, we can obtain: Where j is the imaginary unit and ω is the angular frequency; The amplitude-frequency response of the back-EMF observation error is obtained from formula (8): Since ω<<ω0, we can get from formula (9): Where C is a constant greater than 2; the maximum back EMF error observation amplitude can be expressed as: in For x 12 The derivative of is expressed as: From formula (12), we can get The upper bound of is: From formula (13), we can get e 12 The absolute value at time t in the time domain is: Similarly, the current observation error e can be obtained 11 for: From equations (14) and (15), we can get the current observation error e: 11 The back EMF observation error e 12 Relationship: |and 11 |Cω0=|e 12 | (16) From formula (14), the adaptive law of back-EMF observation error of the extended state observer with the speed change can be obtained as follows: in is the rated maximum back-EMF observation error value; S2: According to the back-EMF observation error adaptive law, a speed adaptive extended state observer is constructed to obtain the equivalent back-EMF observation value of the α-axis in the two-phase stationary coordinate system of the permanent magnet synchronous motor. and the equivalent back EMF observed value of the β axis S3: The back EMF observations are processed using a phase-locked loop based on an extended state observer to obtain the estimated speed of the permanent magnet synchronous motor. and the angle estimate 2. The position sensorless control method according to claim 1, characterized in that: The speed adaptive extended state observer in step S2 is obtained by substituting the back-electromotive force observation error adaptive law into the extended state observer in step S1.

3. The position sensorless control method according to claim 1, characterized in that: The step S3 specifically includes: The back EMF observation value based on the output of the speed adaptive extended state observer is used as the input of the phase-locked loop, and the angle error is calculated according to the following formula: The derivative relationship between the motor electrical angle, speed, and angular acceleration is: Among them: a e is the angular acceleration, d is the derivative of the angular acceleration; let: x 21 =θ e , x 22 =ω e , x 23 =a e ; Convert equation (19) to: The extended state observer in the phase-locked loop is established by equation (20): Where: e 21 Represents θ e The observation error value of z 21 Represents θ e The observed value of z 22 Represents ω e The observed value of z 23 Indicates a e Observed value of β 21 , β 22 , β 23 is the feedback gain coefficient of the extended state observer; From formula (21), the transfer function of the phase-locked loop position estimation based on the extended state observer can be obtained as: Where s represents the complex frequency; according to the bandwidth method, the observer gain is adjusted as: [b 21 b 22 b 23 ]=[3σ0 3σ0 2 s0 3 ] (23) Where σ0 is the bandwidth of the extended state observer in the phase-locked loop.

4. A position sensorless control system, characterized in that: include: Design module, which is used to build an extended state observer based on the permanent magnet synchronous motor model, establish a transfer function between the observation error of the back-EMF of the extended state observer and the derivative of the back-EMF, and design the adaptive law of the back-EMF observation error of the extended state observer with the change of the speed; the specific implementation process is as follows: First, establish the mathematical model of the permanent magnet synchronous motor in the two-phase stationary coordinate system: Where: i α 、i β are the α and β phase stator currents respectively, i αβ =[i α i β ] T 、u αβ =[u α u β ] T and e αβ =[e α e β ] T are the stator current, stator voltage and back EMF in the two-phase stationary coordinate system respectively; R, ψ f , k e and L s Respectively represent the stator phase resistance, rotor flux, induced electromotive force coefficient and inductance parameter values; ω e is the rotor electrical angular velocity, θ e is the rotor electrical angle; i α 、i β The collected three-phase current i a ,i b ,i c After 3s / 2s transformation, we get: u α 、u β The stator voltage given value u d 、u q After 2r / 2s transformation, we get: According to the mathematical model of the permanent magnet synchronous motor in the two-phase stationary coordinate system, an extended state observer is established with the stator current as the state variable and the back electromotive force as the extended variable. The back electromotive force of the α and β axes is taken as the state variable of the expansion, and x 11 =[i α i β ] T x 12 =[-k e e α -k e e β ] T =f, u=[u α u β ] T , expand (1) into the following formula: Then the extended state observer is established: where e 11 represents the stator current observation error, β 11 , β 12 is the feedback gain coefficient of the extended state observer; z 11 =[z 1α z 1β ] T represents the observed value of the stator current in the two-phase stationary coordinate system; z 12 =[z 2α z 2β ] T represents the observed value of the back EMF, k e =1 / L s ; From equations (3) and (4), the error equation of the extended state observer can be obtained as follows: where e 12 represents the back EMF observation error; The α and β phases are symmetrical. Taking the α phase as the object for analysis, the transfer function between the observation error of the extended state observer and the back EMF can be obtained from equation (5): Where s represents the complex frequency; Assume β 11 -A=2ω0、 Where ω0 is the bandwidth of the extended state observer, and equation (6) is transformed into: Transforming equation (7) into the frequency domain, we can obtain: Where j is the imaginary unit and ω is the angular frequency; The amplitude-frequency response of the back-EMF observation error is obtained from formula (8): Since ω<<ω0, we can get from formula (9): Where C is a constant greater than 2; the maximum back EMF error observation amplitude can be expressed as: in For x 12 The derivative of is expressed as: From formula (12), we can get The upper bound of is: From formula (13), we can get e 12 The absolute value at time t in the time domain is: Similarly, the current observation error e can be obtained 11 for: From equations (14) and (15), we can get the current observation error e: 11 The back EMF observation error e 12 Relationship: |and 11 |Cω0=|e 12 | (16) From formula (14), the adaptive law of back-EMF observation error of the extended state observer with the speed change can be obtained as follows: in is the rated maximum back-EMF observation error value; A construction module is used to construct a speed adaptive extended state observer according to the back-EMF observation error adaptive law to obtain the equivalent back-EMF observation value of the α-axis in the two-phase stationary coordinate system of the permanent magnet synchronous motor. and the equivalent back EMF observed value of the β axis A control module is used to process the back EMF observation value using a phase-locked loop based on an extended state observer to obtain a speed estimation value of the permanent magnet synchronous motor. and the angle estimate 5. A position sensorless control device, characterized in that: include: One or more processors, one or more memories, and one or more programs, wherein the programs are stored in the memories and configured to be executed by the processors, and when the programs are loaded into the processors, the steps of the position sensorless control method according to any one of claims 1 to 3 are implemented.

6. A storage medium for position sensorless control, characterized in that: The storage medium stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a processor, the processor executes the steps of the position sensorless control method according to any one of claims 1 to 3.

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